Such dielectric barrier discharge lamps have been disclosed in different ways in the prior art and are of interest, owing to various advantageous technical properties, in particular for backlighting displays, for example computer monitors and television screens, or for office automation applications. In the lastmentioned case, lamp shapes which are in the form of elongate rods are generally used which can be used to illuminate documents in scanners, fax machines, copiers or the like. Those discharge lamps having a discharge vessel which is elongate in the form of a tube are likewise already known and accessible. They may also be of interest for other applications, for example as UV radiators for specific technical processes. The present invention is not restricted to a specific application.
Dielectric barrier discharge lamps cannot be operated using a direct current owing to the discharge mechanism which has been outlined in brief, but are operated either using unipolar power supply pulses or using bipolar power supply pulses. The frequencies used are generally of the order of magnitude of a few 10 kHz.
The discharge lamps described which are elongate in the form of tubes have electrodes oriented along the longitudinal extent. This does not necessarily mean that the electrodes need to run as simple, straight strips parallel to the direction of longitudinal extent. They may also be designed to be meandering or to have another form, but overall run along the longitudinal extent. The invention relates to discharge lamps, in which at least two electrodes are fitted outside the discharge vessel, i.e. to its outside. In the prior art, both designs having inner electrodes and those having outer electrodes are known. Outer electrodes generally provide for more simple production but tend towards certain minimum thicknesses of the dielectric layer between the electrode and the discharge medium since the discharge vessel wall itself acts as said dielectric layer.
It is already known to fit such outer electrodes by means of adhesive bonding or by means of transparent film sleeves surrounding the entire discharge lamp.
Contact is generally made with the electrodes by means of soldering or so-called crimping connections. Contact is made with cables which produce a connection to a ballast for the purpose of operating the discharge lamp.